Hospital acquired infections, i.e., illnesses acquired after hospital admission, cause about 100,000 deaths and cost between $36 billion and $45 billion in the US each year. Almost all of those infections are preventable, and proper hand hygiene is the most cost effective way to prevent them. The objective of the work proposed here is to develop Hand Hygiene for Patients (HHfP), a means to increase hand hygiene by hospital patients after using the toilet, thereby blocking the transmission of infectious organisms on hands potentially contaminated by fecal matter. HHfP will electronically detect toilet use in the patent bathroom, and soap use and sanitizer use in both the patent room and the patient bathroom, without requiring patients to wear a badge or tag. When and only when it finds toilet use without subsequent hand hygiene, HHfP will play a voice message, in the patent's room, reminding them to wash or sanitize their hands. Our previous work with a similar subject population suggests that patients will respond by significantly increasing their hand hygiene, which is quite low at present. They will thereby transmit fewer infectious organisms to themselves. They will also improve public health by transmitting fewer infectious organisms to healthcare workers, to other patients and to their family. There is no other proactive intervention designed to increase hand hygiene in that population.